Kappa Senoh was born in Kobe, Japan, in 1930. His given name was Hajime, which he later changed to Kappa. His father was a tailor, and both his parents were Christians, a minority faith in Japan. As a boy, Senoh demonstrated a talent for drawing, and on leaving school a few years after the end of World War II, he worked as a graphic designer. When he was in his twenties, he became a stage designer. He has since been the set designer for numerous operas, theater productions, and musicals and is recognized as one of Japan's leading designers. He has won many awards for his work.

Senoh is also a best-selling essayist and illustrator in Japan. He is particularly well-known for his travel book series Kappa Takes a Look at . . . which describes various parts of the world and is notable for Senoh's detailed drawings.